Elasto-plastic window glazing compound



Patented May 21, 1946 HUNITED. STATE s PATENT oi-"rics ELASTO-PLASTIO WINDOW GLAZING Grant S. Merrill,

COMPO St. Paul, Minn.,

UND

assignor to Minnesota Mining & Manufacturing Company, St. Paul, Minn., a corporation of Delaware No Drawing. Application February 21, 1941,

Serial No. 380,018

2 Claims. (01. 260-4) a number of well recognized disadvantages,

among which are its tendency to shrink and pull away from the sash and/or, glass, brittleness and tendency to crack and fall off, thus leaving the seam unprotected, etc.

It is an object of this invention to provide a window sash of an improved nature over sash glazed with the types of putty or glazing-compounds heretofore employed. A further object of thi'sf invention is to produce glazed sash in which the'glazing material is of elasto-plastic character, so that it will yield internally with such distortion or warping of various parts of,

the sash as may occur during handling or use, and yet will still firmly adhere tofthe glass and to the wood, metal or other type of material out of which the sash frame is made; A further object is to provide a glazing compound which can be applied with a glazing gun, as distinguished from a compound adapted only to be appliedwith a putty knife or glazing knife, A further object is to provide a glazing compound which will maintainv an approximately uniform viscosity during storage, can readily be forced through a relatively small orifice or opening ofa glazing gun by air or hydraulic pressure during glazing at ordinary room temperatures, has the property of adhering and remaining in place on vertical seams or surfaces while drying, and which has other advantages. These and other objects and advantages will appear from the specification taken as a whole.

In the manufacture of glazing cements, especially those adapted for use in glazing window sash, wherethe surface of the glazing compound is commonly exposed to the weather during use, many different features have to be considered. Not necessarily listed in order of importance, nor even completely, they may be stated as comprisins reasonable cost; ease in handling; adaptability to be applied to desired surfaces or seams by air pressure, such as may be appliedwlth a glazing gun, as above suggested; ability to remain in place, and to dry at a speed which will permit of storage or shipment of the glazed sash unhampered by too delicate precaution; good adhesion to glass,- wood and metal, or the like; freedom from sagging and sliding during application to horizontal or vertical seams and/or putty rabbetts; drying without substantial checking, cracking or pulling away from. the glass, wood, or like surfaces; imperviousness to water seepage both in the body of the glazing composition and at the points of contact with glass, wood and metal; than normal sun temperatures and quickly alternating extremes of heat and cold.

Many of these requirements are not met by the putties in common use, due to weakness such as absorption by the wood of the oils used as plasticizef, thus resulting in weakness of the bond at the juncture with subsequent detachment of the putty.

By the use of a proper combination of such materials as rubber, resins such as rosin or the like, filler material, fibre and solvent, I have found that it is possible to obtain a more intimate bond between the glass and wood, or glass and metal, and the like, than was art putties known to me. The evaporation of the solvent should be fast enough to permit a desired rate of drying and firming, but slow enough to inhibit or prevent bubbling and blisterm Illustrative of various materials'which may be used in forming my elasto-plastic glazing compositions, are reclaimed rubber, such as whole tire reclaim and inner-tube reclaims, raw rubber,

melted scrap inner-tubing, certain synthetic rubbers, certain rubbery synthetic resins, and the like. All such materials are characterized by their elasto-plastic nature and may be referred to as 'elasto-plastomers.

Melted scrap inner-tubing is, in general, less desirable than such forms of rubber as reclaimed rubber. However, melted inner-tubing does have the virtue of requiring less solvent and has some advantage where a very high solids content is desired but, on the other hand, the glazing compound made therewith, unless bolstered with other forms of rubber, does not firm up to the same degree as, for example, compounds made with reclaimed rubber, and various synthetic rubbery compounds.

Where reclaimed rubber is employed, it is desired to have the same substantially free from and, ability to withstand higher possible with prior fibre bundles, especially where the glazing comcompounds.

- materials as Dixie clay tonite)', Asbestine I silicate of needle-like crystal '1' line'strimture'), slate flour, and whiting (calcium producing a punky,

and fan adhesion to 1 that desired under normal drying conditions, and

- ,In many formulations, slate flour slimy portions, thereof or obviate blistering Such quantities of r largerquantity of solvent and this, in-turn,

- fed a pr'oblem in avoiding a fstrlng'y product. a The use ofasbestos fibre materially pound is to be applied with a glazing gun under air-pressure (according to the preferred mode of applying by glazing compound) in order that the gun will notbe obstructed or clogged or application otherwise impaired. However, absence of such fibre bundles or unbroken down fibre is desirable even where with a knife.

In respect to the resincontent'of the composi-.' tion, as for example where reclaimed rubber is I have employed-wood-rosin such as (manufactured by General Naval Stores) and also have used other resinsin'cluding those cumar and like resins, which are employed,

derivable from the same. is to be applied of the coumarone-indene type, e. g.

' mass into an.

of a smaller particle being 'a preferred filler in my composition.

Itis desirable in the commercial production of my glazing compositions, where asbestos fibre is employed, to mill the asbestos and rubber together .on a rubber mill, before introducing the internal mixer. Otherwise, it is difficult-to contr'ol other qualities of the glazin composition asfdesired without ending up :with we a compoundwhich tends to be somewhat dry and to have asomewhat reduced adhesion to wood;

glass and metal, and also has some tendency toward permitting cracking of the glazing compound, especially at the comers of the sash. The

coal tar naphtha. I have also employed Nev illite resin (a resin which may be derived from coumarone-indene typevresins by hydrogenation,

e. g. with Raney Nickel catalyst, and made and sold by thefNeville Company, Pittsburgh) along withforms of rubber including reclaimed rubber.

The'same is advantageous, but, at the present 4 time, is relatively costly for use in window glazing descriptions of hydrogenationtechniques, in this, connection, see U.v S. patent (For to .Carmody, No. 2,152,533, issued March 28, 1939,

' 32, pages 684-92, May, 1940.)

,-I have also employed modified resin such as zinc treated andlime treated rosins, such as socalled. "Zitro and Fosfo! .(sold by General Naval abovediscussed. p v The selection of a satisfactory filler from such size compared with bentively large particle.

(a variety of talc or hydrated magnesium carbonate), and other like materials presented difficulties, and further difiiculties were encoun tered indetermining the quantities desirable to.

body to the composition without non-cohesive mass with poor (especially in a glazing gun) glass, wood and metal below give satisfactory application qualities especially under the more rapid or drastic con-' vdition'oi! drying sometimes encountered. -.Whiting was found, in general, all things considered, to be the most satisfactory Dixie clay, or the like, howfiller but comparatively large proand Industrial and Engineering Chemistry, vol.

' vent is favored Dixie, clay also appeared to be responsible for a livering condition, encountered in various formulations, which was obviated by the used! whiting in place of Dixie clay. The use of'whit-.

ing, or other suitable filler, of comparable partiele size, along with suitable quantities ofother ingredients, particularly those he'reinabove disshort cussed, finally led toa product of desired and buttery consistency, but which .flows "freely some glazing gun tip -(e. gotinch in diam- -eter)', and flows without-thatfstringy! quality which makes satisfactory application practically impossible, particularly at thecorners of the sash. fIhe cornersof the sashare one location, above all others, where a good bond should be attained.

- The use of a relatively high boiling point $01-* in that it makes for easy handling of the glazing'composition, with the danger of fStores) but, in general, such metallic rosin-ates have not been as'advantageous as rosin'itself, and

' .certain other'resins, 3

(a'kaolin clay of a rela-.

skimming over (due to rapid evaporation of the solvent) eliminated orsubstantially so.j '1oo.

rapid evaporation. of the solvent-,was also found to result in cracks or pinholesin the composition .on the'glazed sash. Suitable solvents will be illustrated hereinbelow, rate of evaporation and cost being important considerations.

waxes, though lending water-resisting qualities to the glazing composifor most production uses Formula I Red-inner tube reclaim lbs 400 v Limed FFwood rosin (4.1bs. lime for 100 lbs.-' rosin) -a lbs 600 Finely. divided kaolin lbs 800 Short fibre asbestos lbs 260 ever, ordinarily "necessitated a proportionately creatphase and it was found that prolonged agitation 5 of the mass in an internalmixer-(a-g. of the Werner-Pfieiderer type or Baker-Perkins type) subsequent to the addition of the asbestos, helped to reduce or inhibit sagging or flowin'goif .such a cement after application to window sash. "However, even with the use of asbestos fibre or equivalent, I still prefer a filler material having a substantially larger particle size than Dixie clay, but

helped this i ple Gappearing on page 8 of the co-pendi'ng ap tions, slowed up drying and firmin 0f the glazing composition to anextent that was undesirable in the glazing of sash.'

It was therefore desirable to developa composition of good waterproof qualities in the absence or substantial absence of such an inhibitor of-drying and firming. v The following is illustrative of one .of the early compositions developed to provide an elasto-plastic glazing composition. Y

A petroleum hydrocarbonmaterial having a. distillation range-of to 12050., 19ei= to, 248 F..- gals In: this connection referenceis made to Examplication of Merrill etal., Serial-No. 262,176,-fil'e d March 16, 1939. The present application, inso-- far as it possesses related or common disclosure, is

a further. development or continuation-impart of the aforesaid application. g

, Though the 'composition shown in the above formula has decided advantagesover linseed {oil putties and thelike, I have found that-by-the' use of different formulations I am able to produce 7 size than slate flour, whiting 4 "Various compositions employing waXes Were experimented with, in a search for extreme waterproofness: Ho'weventhe glazing compositions which are appreciably superior, both in respect to their use during glazing of sash and in respect to the resulting glazed sash. An improved composition which I have The composition of Formula II was superior to that of Formula I, among other things, in resisting, in the dried state, cracking at the corners of the window sash and tendency to pull away from the glass, wood or metal'during drying and aging. It is also superior in that its viscosity aging is much better; that is, it maintains an approximately constant viscosity throughouta prolonged storage, in containers, prior to use. These improvements are. of highly important consequence, as will be readily appreciated from what has been said hereinabove with regard to the desirable and necessary qualities in successful glazing cement compositions. From what has been said hereinabove, it will be observed that (1) the use of rosin,

instead of limed rosin; (2) the use of whiting in place of kaolin; and (3) the use of a solvent which evaporates less rapidly, are features of composition which contribute .to the improved qualitiesof the composition of Formula II.

Because of the various qualities desired-and needed in a glazing composition of this kind, as will be evident from the discussion given herein,-

. above, it will be observed that the difference in efiect of whiting over Dixie clay, for example, influences .various other qualities which must be otherwise compensated for in the formulation of glazing cement. Whereas 800 lbs. of kaolin (e. g.

Dixie clay) were employed in Formula I with 400 lbs. of rubber, an appreciably lower amount of whiting was employed in Formula II in relation to the rubber. This is simply illustrative.

A further composition which I have developed, having advantages over both of the compositions of Formulae I and II, is as follows:

Whilethe compositions above set forth may be iormulated'in various ways, onesuitable and advantageous method of formulation (in connection with which the composition of Formula II may be especially considered) is as follows: The rubber and asbestos fibre are milled together on a rubber mill, preferably only long enough (about 10 or 20 minutes) uniformly to disperse the fibre in the rubber. The resulting blended rubber and asbestos fibre may then be taken off the rubber 'mill and introduced into an internal mixer e. g. of the Baker-Perkins type. The whiting and rosin are then gradually added to the rubber in increments with continued mixing, the whiting and the rosin being added alternately. Each of these I ingredients may be added as fast as permissible without breaking up the coherency of the mass. For example, about one-half the whiting, or

slightly less, may be added and, after several minutes of mixing, about one-half of the rosin or other resins, or slightly more, may be added; Then, after several more minutes, the remainder of the whiting may be added and about five minutes later the remainder of the rosin or other Formula III Pounds Red inner-tube reclaim (neutral or of low alkalinity) 800 Wood rosin (Solros) 400 Cumar (M. P. 125-135 C.) t 800 Whiting (powdered calcium carbonate) 800 7 R. asbestos fibre (short fibre) 40o Hydrocarbon solvent (305-365 F.-boiling range, spec. grav. 0.757) 1,514

observed that regular putties are not considered satisfactory on doors, one all-sufiicient reason being their lack of shock resistance.

.of window sash, doors and the like. It is to be resin may be added. An important thing throughout the mixing is, on the one hand, to avoid getting too much molten resin present at one time in order to prevent the batch breaking up into slippery lumps which do not readily reunite into the desired doughy condition and sometimes create a permanently lumpy condition in the finished cement and, on the other hand, to avoid getting so much whiting or comparable filler into the batch at one time that it becomes crumbly' and lacing in coherency, thereby to maintain a proper balance to promote good mixing. Ordinarily no heat need be added or withdrawn during the foregoing mixing operation. The rubber and asbestos blend is warm when it comes from the rubber mill and the mechanical mixing ordinarily generates about the right amount of heat to promote good mixing. However the temperature can be controlled, if desired, by'the addition of either cold water or steam to the jacket of the internal mixer.

After the solids of the composition are uniformly mixed together to'provide a substantially uniform blend, thesolvent may then be grad ency of the mix. Ordinarily enough solvent is added to bring the viscosity of the desired glazing cement to,- for example, approximately 3 minutes at.75'F., where the viscosity is'measured by the time required for one-half pint of glazing composition to pass through a pipette type viscosimeter having a pipe 8 inches long and of one-fourth inch diameter, under a pressure of 60 lbs/sq. in. gauge.

The composition of Formula III, as well as that of Formula I, may be formulated according to generally the same method. In the composition of Formula III, the cumar and Solros resins may be mixed together and added in increments, or increments of each material may beadded separately, as desired.

. It will be understood that the above formulae are given by way of illustration and not by way of limitation. It will be evident that the compatible with, rubber.

jstantially hindered. Likewise, 'as above indicated, in place of various types of ordinary rubber, various rubbery vinyl resins, such as vari- ;ous but'yral resins, synthetic rubbery compositions such as Vistanex, etc., may be employed. Likewise wood rosin may be replaced wholly or in part by such materials as ester gum, Nevillite resin, and various other natural and syntheic resins. As illustrated in Formula 111, such resins as cumar may be employed to advantage along with such a resinous material as wood rosin.

, materials as blanc-fixe, barytes, or other common rubber and paint fillers of sizes comparable ing composition. Whereas sash glazed with ordinary linseed oil putties have a tendency to wrinkle as a result of slight distortion of the sash during handling in shipping, sash glazed according to the present invention are free of such'tend- V encies, particularly in view of the elasto-plastic nature of my glazing composition.

All embodiments 01' this invention are comprehended within the scope of the following claims.

What I claim is:

1. An elasto-pla'stic sash glazing composition having good adhesion to wood, glass and metal and of such viscosity that it can readily be applied at ordinary room temperatures to the putty rabbett of a sash by forcing sag appreciably after application andduringdry-' ing in a vertical putty rabbett, said glazing com-; position comprising reclaimed rubber, wood rosin,

- cumar, powdered whiting .and asbestos fiber, disto whiting. In view of the cheapness and ready availability of whiting, it is commonly preferred.

In place of asbestos fibre, various natural vegetable, mineral and synthetic fibres may be used, cotton linters and nylon being examples.

Some attempts have previously-been made to make rubber-containing glazing compositions for use as vso-c'alled knife coating compositions,"

but not at all adapted for use in a glazing gun. While my glazing cements may be applied with a knife, a 'feature of prime importance isthat I they are adapted for application withaglazing gun; that is, they are of viscosity'such'that they can be forced through a small opening (e. g. one-eighth inch'diameter) of a glazing gun under pressure and yet have sufllcient. body, and

other properties, so that, when applied to the putty rabbett of window sash and doors they.

will remain in place without sagging.

' Sash and doors glazed with the preferred compositions hereinabove described may be shipped of the kind-and substantially. in the proportion asfollowsz Pounds Reclaimed rubber 800 Wood rosin i v 400 Cumar resin (M. P. 125 -l35 C.) Powdered-whiting 800 Short fibre asbestos 400 within about 2 days afterapplication ofthe glazpersed in a hydrocarbon solvent having a boil- 1 ing range. of the order of 305 -3655 ;F., said re- 3 f claimed rubber being present in greaterproportion than said rosin but in lesser proportion than; the combined resinous material, said powdered whiting being present in substantial but lesser.

proportion than the combined rubber and resin content, andthe asbestos fibre being present in substantial but lesser amount thansaid whiting.

2. An elasto-plastic sash glazing composition.

having good adhesion to wo d, glass and metal and comprising an intimate blend of ingredients Hydrocarbon solvent (305 -365 F. boiling range and specific gravity oithe order- 01.0.75?)

r the same under' I pressure through a confined passage of a glazing gun, andfurther of such body that it willnot soo- 

